Seed planters, often referred to as “sowing machines,” are well known and are used to plant seeds of a wide variety of shapes and sizes. Such machines include a frame having a seed hopper holding a plurality of seeds to be planted. Typically, to control the spacing between planted seeds, sowing machines include a blade or furrow opener for digging a channel into which seeds are deposited by a metering head. After a seed is deposited into the furrow, a furrow closer and packing wheel follows to cover the seed.
Currently, a wide variety of metering heads are used to deposit seeds into a furrow. One such example is disclosed in U.S. Pat. No. 3,636,897, issued to Brink. Brink discloses a disc-shaped metering head having a plurality of individual pockets formed around its perimeter. The metering head is rotated into and out of communication with a seed hopper where seeds are deposited into each of the individual pockets. As the metering head continues to rotate, the seeds are dropped into a furrow formed by the sowing machine by gravity. A similar metering head is disclosed in U.S. Pat. No. 3,888,387, issued to Deckler. The metering head of Deckler also includes a plurality of equally spaced, seed receiving pockets about a periphery of the metering head. Such pockets are sized to receive at least one seed for planting by rotational movement of the metering head.
Another type of metering head is disclosed by U.S. Pat. No. 3,706,396, issued to Knapp et al. The metering head of Knapp et al. is a disc-shaped turret that includes a plurality of outwardly opening and vertically extending slots sized to receive a seed. The turret is rotatably mounted on a frame, such that as the turret is rotated, the slots are progressively moved into and out of an opening for planting in a furrow.
Thus, currently available metering heads include a plurality of individual pockets or slots formed around a perimeter of a disc-shaped wheel, wherein each individual pocket is sized to receive at least one seed. Although such metering heads are effective for sowing machines, they are not without their problems. As an example, because the metering head includes a plurality of individual, non-continuous pockets formed around a perimeter, the sowing apparatus must include some timing mechanism to deposit seeds within each individual pocket or such individual pockets will lack a seed for planting. This results in the undesirable effect of having too much space between seed plantings. As a result, there exists a need for an improved metering head for sowing apparatuses.